Answer: The end of the anchor line is 42.53 feet from the base of the tower.
The wording in your question is a little unclear. I assume that you are looking for how far the anchor line is from the base of the tower.
If so, you can use the Pythagorean Theorem.
a^2 + b^ = c^2
96^ + b^2 = 105^2
Solve for b, gives you about 42.53.